Sex Chromosome Variation in Denmark

A 20 year old study - but still good science.
Sex Chromosome Abnormalities Found Among 34,910 Newborn Children: Results From a 13-Year Incidence Study in Århus, Denmark J.Nielsen and M.Wohlert in Birth Defects: Original Article Series, Volume 26, Number 4, pages 209-223

Chromosome examination was made of 88% (34,910) of all 39,618 live- born children at the Maternity Hospital in Århus during a 13-year period from 1969 to 1974 (4 years, 5 months) and from 1980 to 1988 (8 years, 7 months).

This paper deals only with the sex chromosome abnormalities. Autosomal abnormalities will be presented elsewhere.

Klinefelter syndrome was found in 1 per 596 boys, XYY in 1 per 894 boys, triple X in 1 per 1002 girls, and Turner syndrome in 1 per 2130 girls. Other sex chromosome aberrations were found in 1 per 11,637 children. The total incidence of sex chromosome abnormalities was 1 per 448 children or 2.23 per 1000.

Karyotype	Number
47,XXY	20
46,XY/47,XXY	7
46,XX(male)	2
48,XXYY	1
47,XYY	18
46,XY/47,XYY	2
47,XXX	17
45,X	1
45,X/46,XX	2
45,X/47,XXX	1
45,X/46,X,r(X)	1
45,X/46,X,inv(X)**	1
45,X/46,X,i(Xq)/47,X,i(Xq),i(Xq)	1
45,X,inv(9)/46,XX,inv(9)	1
45,X/46,XY (male)	1
46,XX/ 47,XX,del(Yq) (female)	1
46,XX/46,XY (female)	1
Total	78

What was that about "boys are 46Xy, girls 46XX, and the others only one in a million" again?

Of course most Intersexed children don't have such obvious chromosomal variation from the norm. 1 in 500 girls have Congenital Adrenal Hyperplasia(CAH). Then there's those with Persistant Mulleriam Duct Syndrome(PMDS), Complete Androgen Insensitivity Syndrome(CAIS), Partial Androgen Insensitivity Syndrome of various degrees (PAIS), 5-alpha-reductase-2 deficiency syndrome (5ARD), 17-beta-hydroxysteroid-dehydrognase-3 deficiency syndrome (17BHDD), 3-beta-hydroxysteroid-dehydrognase-3 deficiency syndrome (3BHDD) which can also cause CAH, Vaginal Dysgenesis, Gonadal Dysgenesis, and so on and so on, from minor mutations, environmental causes, or timing glitches.

None of those are counted in the above.